SEOUL - North Korean leader Kim Jong Un, during his summit with Russian President Vladimir Putin, said peace and security on the Korean peninsula will entirely depend on the future U.S. attitude, state media Korean Central News Agency (KCNA) said Friday.

Kim's remarks are seen as keeping pressure on the U.S. to be 'more flexible' in accepting Pyongyang's demands to ease sanctions, compared to the U.S. stance during the collapsed second U.S.-North Korea summit in February in Hanoi, as he said earlier this month.

Kim said at the time he will wait 'till the end of this year' for the United States to change its mind.

'The situation on the Korean peninsula and the region is now at a standstill and has reached a critical point where it may return to its original state as the U.S. took a unilateral attitude in bad faith at the recent second DPRK-U.S. summit talks,' KCNA reported Kim saying, using North Korea's official name, the Democratic People's Republic of Korea.

Kim invited Putin to North Korea at a convenient time and Putin accepted, KCNA said.

The first face-to-face talks between Putin and Kim, held Thursday on an island off the Russian Pacific city of Vladivostok, did not appear to have yielded any major breakthrough.

The two leaders had an in-depth discussion on the ways for the two countries to promote the strategic communication and tactical collaboration in the course of ensuring peace and security on the Korean peninsula and in the region, KCNA said.

Putin said afterward he thought a deal on Pyongyang's nuclear program was possible and that the way to get there was to move forward step-by-step in order to build trust.

But any U.S. guarantees might need to be supported by the other nations involved in previous six-way talks on the nuclear issue, Putin said, which was seen as an attempt to use the summit to strengthen Russia's diplomatic clout as a global player.

Both Russia and North Korea agreed to take positive measures in several fields in order to further cooperate in trade, economy, science and technology, KCNA said.